This is one of the most common skin problems. Most people have them, and just a few fortunate ones are exempt from them due to amazing genetics.
Stretch marks are long lines of a different color from the skin around them. Anyone can develop them, but some people are prone to have them more than others. They tend to affect more women than men.
They can appear on several body parts, like the tummy, hips, lower back, thighs, upper arms, and breasts as a result of a sudden stretching of the skin.